On a commercial farm near Ross-on-Wye, west England (sandy clay loam topsoil texture), direct N2O-N emissions were measured from replicated (x3) plots (5 x 15 m) arranged in a randomised block design. Cattle slurry (c.40 m3/ha), broiler litter (6.5 t/ha) and layer manure (6.5 t/ha) were applied to cereal stubble in the autumn (early-September) and to winter wheat in the spring (late-February). Cattle FYM (30 t/ha) was also applied in the autumn. The cattle slurry was applied using the ADAS small plot applicator set up for surface broadcast and trailing hose application. The solid manures were spread by hand. In the autumn the surface broadcast cattle slurry and the poultry manures were incorporated within 24 hours of application. An untreated control treatment was included where no manure was applied. Following manure application, measurements of direct N2O-N were made over c.12 months, using 5 static chambers (0.8 m2 total surface area) per plot and analysed by gas chromatography. In a separate area of the plot, a wind tunnel technique was used (one per plot) to measure ammonia-N emissions for 7 days after each cattle manure application and for 21 days after each poultry manure application. Grain yields and total N offtakes were measured following harvest in August 2013.
The Herefordshire, 2012-13 manure experiment contains data sets of; annual nitrous oxide emission, annual nitrous oxide emission factor, total ammonia loss, soil moisture, top soil mineral nitrogen (selected dates), temperature, rainfall and associated crop (yield, total and grain nitrogen offtakes) and soil measurements.

Data Quality Statement:The ADAS Integrated Management System (AIMS) is a business centered management system that effectively integrates business planning, business management and business processes. It also ensures that all the requirements of proprietary quality, environmental management and Health & Safety related standards and schemes to which the ADAS Group of Companies complies are addressed in the one company wide management system. At the core of AIMS are the Group’s policy statements, quality and environmental management system manual and an extensive range of Standard Operating Procedures prescribing internal business processes and technical methodologies.
All documents within AIMS are periodically reviewed and revised where necessary, in accordance with a documented procedure so that the Group’s business needs continue to be met and to respond to opportunities and ideas from staff for further improvement. The system is centrally controlled and all documents are available to staff with password controlled computer access via the company’s Intranet. Copies of policy statements and the quality and environmental management system manual are publicly available via the company’s website: www.adas.co.uk. Hard copies of these documents can be provided where necessary.
Senior management periodically review AIMS to ensure the continuing suitability, adequacy and effectiveness of the system and to identify or assess opportunities for further improvement or requirement for change.
Compliance with AIMS ensures that client needs are identified, understood and that services and products are subsequently delivered in a professional and independent manner designed to fully meet and satisfy client expectations.
Delivery to clients is:
- Subject to risk assessment and subsequent risk management.
- Specified and agreed in formal contract agreements.
- Controlled via the use of effective project planning to meet milestones, specifications, time frames and budget.
- Project managed by appropriately trained and qualified staff, using up-to-date equipment and facilities where appropriate.
- Subject to rigorous quality control checking before release to ensure technical soundness and compliance with contractual requirements and ADAS standards.
Effective implementation of AIMS is assessed by scheduled internal audits carried out by independent Quality Assurance staff. Critical aspects of work and that of sub-contractors and collaborators are also audited where contractually required.
ISO 9001
The Soils, Agriculture & Water Business Unit and the Animal Health and Chemicals in the Environment Groups within the Development Businesses Unit are certificated to this standard by Lloyd’s Register Quality Assurance (LRQA) for:
‘Provision of independent research and consultancy focusing primarily on arable crop protection, crop physiology, sustainable farming systems, agriculture, horticulture, soils and nutrients, water, sustainable livestock, animal health and chemicals in the environment (excluding advisory work funded directly by farmers and growers).’
Certificate No. LRQ 0936648.
Each R&D study is led by a Study Director responsible for planning, co-ordinating, controlling and reporting the work. Throughout the work the Study Director has a pivotal role in guiding the scientific content and quality of delivery. A specific protocol approved by the Study Director, sets out the objectives and timetable for the work, and details the experiment design, materials and methods and reporting requirements.
Detailed nitrous oxide emission measurement methodology:
Direct N2O emissions were measured with five static flux chambers (40 cm wide x 40 cm long x 25 cm high) per plot, covering a total surface area of 0.8 m2. The chambers were of white (i.e. reflective) PVC and un-vented with a water-filled channel running around the upper rim of the chamber allowing an air-tight seal to form following chamber enclosure with a lid (Smith et al., 2012). Chambers were pushed into the soil up to a depth of 5 cm and remained in place throughout the experiment, except during manure application, drilling, soil cultivations and harvesting when chambers were removed, locations were marked, and chambers were re-instated to the same position as prior to removal.
Chambers remained open except for a short time on each sampling day. On that day, ten samples of ambient air were taken to represent time zero (T0) N2O samples. From each chamber, after a 40-minute enclosure period (T40) a headspace sample was taken using a 50-ml syringe. Using a double needle system the sample was flushed though a pre-evacuated 20-22 ml glass vial fitted with a chloro-butyl rubber septum and held at atmospheric pressure. The N2O flux was calculated using an assumed linear increase in N2O concentration from the ambient N2O concentration (T0) to the N2O concentration inside the chamber after 40-minutes enclosure (T40) (Chadwick et al., 2014). Throughout each experiment, the linearity of emissions through time was checked routinely from three chambers located on the plots where cattle slurry had been applied by trailing hose machinery. A minimum of five samples were taken from each chamber at 15 min intervals commencing at closure i.e. T0 and spanning the T40 sampling time. In order to permit sampling from a growing crop, when required and at the time of sampling, an additional chamber was stacked (using the water-filled channel) onto each permanent chamber and the chamber enclosure period extended.
In order to minimise the effect of diurnal variation, gas sampling was carried out between 10:00 am and 14:00 pm and where possible between 10:00 am and 12:00 pm as suggested by IAEA (1992) and referred to in the IPCC good practice guidance (IPCC, 2000). Gas samples were analysed as soon as possible after collection (to minimise potential leakage) using gas chromatographs fitted with an electron-capture detector and an automated sample injection system. Following receipt in the laboratory, three replicates of one standard N2O gas were kept with the samples and were used to verify sample integrity during storage. The gas chromatographs were calibrated on a daily basis using certified N2O standard gas mixtures.
An exchange of samples of chamber air and standard gas mixtures between labs from the different research organisations involved in the InveN2Ory programme of experiments who operated the GCs were carried out, to avoid the possibility of any bias in the results towards high or low values.
Following manure application, N2O flux measurements were carried out for 5 days immediately following manure application, daily for a further 5 days during the next week, twice weekly for the next two weeks, every other week over the next c.four months, decreasing in frequency to monthly until the end of the 12 month sampling period. For each manure application timing, this sampling schedule resulted in an annual total of 30 sampling days starting from the day of the manure application. Measurements were taken over 12 months to follow IPCC good practice guidance and so that the results were directly comparable to the IPCC 2006 methodology default emission factor. Nitrous oxide fluxes from the five replicate chambers per plot were averaged. Cumulative fluxes were calculated using the trapezoidal rule to interpolate fluxes between sampling points.
References:
Chadwick, D.R., Cardenas, L., Misselbrook, T.H., Smith, K.A., Rees, R.M., Watson, C.J., Mcgeough, K.L., Williams, J.R., Cloy, J.M., Thorman, R.E. & Dhanoa, M.S. (2014). Optimizing chamber methods for measuring nitrous oxide emissions from plot-based agricultural experiments. European Journal of Soil Science 65, 295-307.
IAEA (1992). Manual on Measurement of Methane & Nitrous Oxide Emissions from Agriculture. International Atomic Energy Agency (IAEA), Vienna, IAEA-TECDOC-674, ISSN 10111-4289.
(IPCC, 2000). Good Practice Guidance & Uncertainty Management in National Greenhouse Gas Inventories. Penman, J., Kruger, D., Galbally, I., Hiraishi, T., Nyenzi, B., Emmanul, S., Buendia, L., Hoppaus, R., Martinsen, T., Meijer, J., Miwa, K. znd Tanabe, K. (Eds). IGES, Japan.
Smith K.A., Dobbie K.E., Thorman R., Watson C.J., Chadwick D.R., Yamulki S. & Ball B.C. (2012). The effect of N fertilizer forms on nitrous oxide emissions from UK arable land and grassland. Nutrient Cycling in Agroecosystems 93, 127-149.Publication Date: